Water from the world’s shrinking glaciers was responsible for almost a third of the rise in sea levels between 2003 and 2009, shows new research.
An international team of scientist compared data gleaned from two NASA satellites as well as traditional ground measurements from glaciers around the world.
Their work, published in the journal Science , is the most accurate estimation of how glaciers contribute to sea level rises to date.
“For the first time, we’ve been able to very precisely constrain how much these glaciers as a whole are contributing to sea rise,” says lead author Assistant Professor Alex Gardner, assistant geography professor at Clark University in Worcester, Massachusetts.
“These smaller ice bodies are currently losing about as much mass as the ice sheets.”
The most significant ice losses occurred in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas, the study found.
The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the period, leading to a rise in ocean levels of about 0.7 millimeters per year.
By contrast the glaciers in Antarctica, smaller ice masses that are not connected to the ice sheet, made scarcely any contribution to sea-level rise over the study period.
Father Martin, parish priest on the island of Abaiang walks through the wasteland that used to be the village of Tebunginako garden. Rising sea water made the soils heavily saline and unable to support the Bananas and Taro vital to the villagers’ survival
Sea level at the Boston tide gauge has risen about a foot (.25 meters) since records began in 1921. Most of that rise is due to the expansion of ocean waters due to global warming, plus increased melting from glaciers and icecaps.
According to an excellent analysis by Andrew Freedman of Climate Central, continued sea level rise in Boston will increase the odds of a 1-in-100 year coastal storm surge flood by a factor of 2.5 by the year 2030. Even given the low end of sea level rise scenarios, and without assuming any changes in storms, 1-in-10-year coastal flooding events in the Northeast could triple by 2100, occurring roughly once every 3 years, simply in response to higher sea levels (Tebaldi et al. 2012).
Nemo arrives just days after a report the nonprofit Boston Harbor Alliance warned of the region’s growing vulnerability to such storm surge events. The report found that coastal flooding of 5 feet above the current average high tide—a 1-in-100 year flood—would inundate 6.6 percent of the city of Boston.
At 7.5 feet above the current average high tide, more than 30 percent of Boston could be flooded, the study found. Boston has gotten lucky two storms in row now—both Hurricane Sandy (storm surge of 4.57’) and Winter Storm Nemo (storm surge of 4.21’) brought their peak surge near low tide, so the water level during these storms did not make the top-ten list, even though these were two of the four highest storm surges ever measured in Boston.
Mr. Burt comments, “it is a bit unsettling that two of the most significant storms in the past 300 years to strike the northeastern quadrant of the U.S. have occurred within just four months from one another.”
Rising sea levels are already making coastal living at low elevations an increasingly precarious proposition in the Northeast. If Sandy and Nemo are harbingers of a new era of stronger storms for the Northeast U.S., the double-whammy combination of bigger storm surges riding in on higher sea levels will make abandoning higher-risk portions of the coast a necessity.
“60 feet” - That’s the amount of beach lost in parts of Martha’s Vineyard island due to Hurricane Sandy. On the map, above, you can see Martha’s Vineyard middle right, just below the “hook” known as Cape Cod. Note the island’s proximity to Boston, Providence, and Manhattan.
The “vinyud” as we Yankees call it, is a beautiful place with fantastic restaurants and beaches. Ultimately, though, it’s a play ground for the very wealthy. Indeed, many Presidents (among other fancy people) regularly vacationed here, including John Adams(!), Ulysses S. Grant, Chester Arthur, John F. Kennedy (actually, the Kennedys have a ton of property here), Bill Clinton, and, yep, Barack Obama. (Mitt Romney, by the way, has two of his six homes in Massachusetts).
One private home worth around $8 million hired engineers, negotiated with neighbors, and won approval from the town for an emergency permit to build a temporary beach erosion protection system.
The emergency plan calls for the installation of a Coir Log Coastal Bank Protection System which will “hopefully temporarily slow down” the rate of erosion, Mr. Sourati said. “It’s not a permanent solution, but it’s going to give us some time to think about other solutions.” Via
A great solution, but it’s just for one house. What about the roads, hotels, schools, research facilities, and countless thousands of homes impacted by sea level rise and aggressive beach erosion? What can be done for an entire coast line, which has already seen a foot of sea level rise?
Sea level has risen by about eight inches overall worldwide since around 1900 and the waters are expected to rise an estimated three feet by 2100. “Sometimes we forget that the damage in New Orleans in 2005 from Hurricane Katrina came not from wind or rain, but from the storm surge [that caused flooding] ahead of that storm,” Lemonick says. If sea levels rise as expected, “all of those storm surges are going to be starting from a level three feet higher, which means that they have much greater potential to drive inland, to wash over barrier islands, and to really inundate the coast. … Many, many millions of people and trillions of dollars of infrastructure are in serious danger, if those projections are correct.”
North Carolina outer beaches erode on average 2 feet per year. Some beaches erode at 8 feet every year. It’s worse when there are storms. This interactive map shows the most vulnerable beaches.
But, that’s not why I posted this chart.
The federal government pays North Carolina to restore these beaches. Beach restoration is an interesting and controversial process. A special boat is launched just off shore. In a process called dredging, the boat scrapes sand from the ocean floor. It then dumps and pumps the sand along the beach. I’ll post a video so you can see it. Some local taxes are used to pay for this, but the majority comes from American tax payers.
This type of beach nourishment is expected to go forever, or at least for as long as people choose to live in the areas. Thus, federal assistance is a sort of perpetual insurance for North Carolinians. In sum, North Carolina’s new law that bans local cities from using climate science are forced to depend on federal assistance to forever take care of their self-mad mess.
Communities in California are learning harsh lessons of sea-level rise. The rate of beach erosion increases, which in turn destroys much of what people have built. At this beach in San Fransisco, parking lots, bike lanes, and buried utility lines are being destroyed by faster than predicted erosion. Thus, there is a choice: build a bigger wall to hold back the sea, or retreat. Some cities have chosen to retreat.
Up and down the California coast, some communities are deciding it’s not worth trying to wall off the encroaching ocean. Until recently, the thought of bowing to nature was almost unheard of.
But after futile attempts to curb coastal erosion — a problem expected to grow worse with rising seas fueled by global warming — there is growing acknowledgment that the sea is relentless and any line drawn in the sand is likely to eventually wash over.
“I like to think of it as getting out of the way gracefully,” said David Revell, a senior coastal scientist at ESA PWA, a San Francisco-based environmental consulting firm involved in Goleta and other planned retreat projects.
The issue of whether to stay or flee is being confronted around the globe. Places experimenting with retreat have adopted various strategies. In Britain, for example, several sites along the Essex coast have deliberately breached seawalls to create salt marshes, which act as a natural barrier to flooding.
A blog about the interactions between the built environment, people, and nature.
I'm a climate change consultant specializing in climate adaptation, environmental law, and urban planning based in the U.S. In addition to traveling and hiking, I research, publish, and lecture on how cities can adapt to climate change.
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